초록 ▼

This invention relates to a method for enhanced recovery of petroleum from a subterranean oil-bearing formation. More particularly, this invention relates to secondary or tertiary recovery of oil employing a polymer thickened aqueous drive fluid. The polymeric viscosifier for the drive fluid is sele

This invention relates to a method for enhanced recovery of petroleum from a subterranean oil-bearing formation. More particularly, this invention relates to secondary or tertiary recovery of oil employing a polymer thickened aqueous drive fluid. The polymeric viscosifier for the drive fluid is selected from a class of hydrophobically associating water soluble polymers containing one or more water soluble monomers and a water insoluble monomer or group. The water soluble groups are acrylamide and a salt of an ethylenically unsaturated sulfonic acid and the water insoluble group is a higher alkyl acrylamide. These polymers, when dissolved in an aqueous brine solution, have the ability to substantially increase the viscosity of the solution. The control of displacement fluid mobility results in more uniform sweep efficiency and improved oil recovery. In addition, aqueous solutions of these hydrophobically associating polymers exhibit enhanced viscosification, reduced salt sensitivity and other desirable rheological properties found useful in chemically enhanced oil recovery processes.

대표청구항 ▼

A water flooding process for the secondary recovery of oil from a production well comprising injecting an aqueous solution under pressure to force oil to the production well, said aqueous solution comprising: (a) water; and (b) about 100 to about 5,000 ppms of a water soluble polymer having the form

A water flooding process for the secondary recovery of oil from a production well comprising injecting an aqueous solution under pressure to force oil to the production well, said aqueous solution comprising: (a) water; and (b) about 100 to about 5,000 ppms of a water soluble polymer having the formula: [Figure] wherein R1 is a C6 to C22 straight chained or branched alkyl or alkylcycloalkyl group; R2 is hydrogen or a C6 to C22 straight chained or branched alkyl or cycloalkyl group or a C1 to C3 straight chained or branched alkyl group; and A is selected from the groups consisting of SO3-M+, phenyl-SO3-M+, and CONHC(CH3)2CH2SO3-M+, wherein n+is an alkali metal or ammonium cation, wherein x is about 5 to 98 mole percent, y is about 2 to about 95 mole percent, z is about 0.1 to about 10.0 mole percent.